The working principle of plate heat exchanger is carried out by heat transfer mechanism. According to the law of thermodynamics, heat is always spontaneously transmitted to low temperature objects by high temperature objects. When in the presence of two kinds of fluid temperature difference, there must be heat transfer, both exist in the process of forced convection heat transfer temperature difference of the fluid, as a result of plate heat exchanger heat transfer surface using leng wave structure optimization design, make its heat exchange rate above 92%, even if the fluid velocity in the Renault must value the following, fluid movement between plates was also three dimensional motion, prompting form intense turbulent fluid, reduce the boundary layer thermal resistance, strengthen heat transfer efficiency. They are heat exchangers for refrigerant fluids (frozen water) and working fluids (cooling circulating water).